Originally Posted by
Canker
the limit screw will get you at least one if not two gears up from the hardest.
That will vary depending on the exact setup, but yeah at least one. If yiu are lucky you might get three.
Then why not wedge something between the end of the limit screw and the point it hits to get a bit more if needed?
If you were that worried about it you could make a little cable end with a set screw that could be adjusted to roughly the right gear and fine tuned with the barrel adjuster. Given how unlikely you are to need it and how many other work arounds there are I wouldn't bother.